Egyptian soldiers in riot gear deployed water cannon and rolls of barbed wire yesterday as they started to close the Gaza/Egypt border, turning back the thousands of Palestinians who have flooded across.

But even as some gaps in the wall were being closed, Palestinians used a bulldozer to puncture another section of the seven-mile border. Several thousand people still crossed in both directions. One crane was set up by the border at Rafah to bring over goods more quickly - particularly cement and fuel, which are scarce in Gaza.

There were some tense moments as crowds pushed up against the soldiers and occasionally threw stones. The Egyptians used a water cannon briefly and shots were fired into the air. But for every gap that was closed, many more remained open. Much of the steel and concrete wall on the Palestinian side remains demolished.

Although Egypt had been willing to let Palestinians flood into the Sinai peninsula over the previous two days, it appears that Cairo eventually hopes to reseal the border and re-establish a formal crossing point. Already Egyptian officials have prevented the Palestinians from travelling into the rest of Egypt. Most of the Palestinians enter to shop for basic necessities after the economic blockade that has been tightened on Gaza in the past two years. Israel, which has not had troops on this border in that time, has announced a security alert for its citizens travelling in Sinai.

Hamas has won considerable public support for demolishing the border wall on Wednesday. Yesterday its officials said they wanted a crossing at Rafah, which has been closed for much of the past two years, to remain open in the future.

"We insist and urge our Egyptian brothers that there must be a mechanism to allow the passage of people and goods through the Rafah crossing in a legal and organised manner," said Taher al-Nunu, a spokesman. Armed Hamas men were also at the border trying to control the crowd.

Senior Israeli officials had suggested Egypt might in future take more responsibility for supplying fuel and food to Gaza, allowing Israel to "disconnect" from the 1.5 million Palestinians living there. But Egypt shows no sign of accepting such a role, despite pressure from the Arab world to ease the plight of Gazans.

Israel's prime minister, Ehud Olmert, and the Palestinian president, Mahmoud Abbas, a rival of Hamas, are due to meet tomorrow for their latest peace process talks. Israel tightened its closure of Gaza crossings a week ago in an effort to prevent Palestinian militants firing rockets into southern Israel, but has since allowed through limited supplies of fuel and aid after widespread international criticism for creating a humanitarian crisis.